Valve-stem-protector hood



W. P. LOWTHER. VALVE STEM PROTECTOR HOOD.

APFLlCATlON FILED APR.16, i919.

mmm?, Patented M3142, 1920,

4 1N VENTOR.

llt)

WILLAM P.'LOWTHER, OFSPOKANE, WASHINGTON.

VALVE-STEM-PROTECTOR HOOD.

inseam.

Specification of Letters Patent.

rarement nar. 2', ieee.

application'let April 16,1919. Serial No. 290,453.

To all whom t may concern.'

Be it known that 1, WILLIAM LOWTHER, a citizen `of the United States,residing at Spokane, in the county of Spokane and State of llVashington,have invented new and useful Improvements Ain Valve-Stem-ProtectorHoods, of whichjhe following is a specication.

This invention relates to an improved protecting device for that portionof an explosion engine valve stem lying between the guide therefor andthe closure thereof.

My invention is adapted for use in connection with either an exhaustvalve stem, an intake valve stem, or both.

ln connection with an exhaust valve stem, one of the main features of myinvention'is to prevent the stem from sticking in its guide and therebypreventing the closure from engaging the valve seat. A further object isto protect the valve stem, throughout its exposed length, from theheating action of exhaust gases How-ing out 'through the exhaustpassage, and which gases would otherwise play'upon and seriouslyatlectthe stein. y

ln connection with the intake valve, itis an object ot my invention toprevent air leakage into the intake passage. from Vbe.v tween the stemand the guide, which leakage, on a loose-working stem, is suilicient tottl materially weaken the mixture'.

ln either utility of my invention it is an object to provide a protectorof suliicient size to surround the valve stem and a portion ,of itsguide with a dead air body, the function of which, in connection withthe exhaust valve stein is to reduce superheating of the stem, andinconnection with the intake valve stein, the function is to present thisdead air body to any leakage ingress thereby neutralizing the eiiect oitthe saine before the flow can enter the intake pas# sage.

lt is a feature of my invention to provide a protecting hood for theperformance of these various functions, and a novel portion of said`hood-consists in an intuined sharp edge for engagement with the steinguide,

peripherally thereof.

@ther objects andeatures of this invention will be more Jfully describedin connection with the accompanying drawing and will be moreparticularly pointed out in and by the appended claims.

Figure 1, is a sectional view of a portion of an engine structureillustrating an intake valve provided with the device of my invention,the same being shown in section.

Fig. 2 is a sectional view showing the device of my invention applied toan exhaust lvalve.

F ig. 3 1s a sectional view on line 3-3 ofv Fig.

F ig. 4 is a vertical sectional view of my improved protecting devicedetached from the valve stem. l

Like characters of reference designate similar parts throughout thediierent iigures of the drawing.

As illustrated. 1 designates the intake valve chamber .of an explosionengine and 2 designates the passage chamber, ingress of the mixturebeing through opening 3. An intake valve closure 4 is shown coactingwith a seat 5 andfprovided v'with' a stem 6. The

stein 6 extends through a guide 7 toward the operating mechanism whichvis not shown. y l

lullig. Q, l have illustrated an exhaust valve chamber 8, having 'anexhaust valve 9 coacting with the seat 10. rlhe exhaust chamber 11communicates to an exhaust out- Y let 12. The valve closure 9 has a stem13 which extends through a guide 14 toward operating mechanism therefor,not shown.

lThe device of my invention takes an identical form when used either foran exhaust or an intake valve.` As illustrated, 'my protecting device isin the form of a hood having a contracted neck portion :15, adapted tosnugly t the valve stem 6 or 13, with .its end in abutting edgewiseengagement at 16, against the lower edge of the valve closure. A pin 17may serve to positively unite the hood with the stem. From this neckportion .-15 the device .is appreciably en-` larged, as at 18, in such amanner as to extend in relatively considerablel spaced rela` tion fromboth the stem andthe guide. The lower edge 19 is inturned and is alsopreferably sharpened so as to4 engage the periphery of the guide 7 withaproper working iclearance,l This engagement will not be such stem. Toomuch stress cannot be laid upon the complete inclosure of that portionof the valve stem between its guide and closure, es-

pecially in the case ot' an exhaust valve.

In an exhaust valve, the gases frequently condense and mix with thelubricant and there is a chemical reaction which destructively affectsthe valve steni. -Not only the lubricant but the condensed gases areentirely' prevented from reaching the valve stem when the same isequipped with my device. Normally, the exhaust valve stem is subjectedto a very severe heating actionwhen the burnt gases flow out through theexhaust passage,I which is entirely avoided by the use of my invention.

Carbon deposits, especially on the exhaust valve stem and its guide willfrequently cause an interrupt-ion or stoppage before the st-em hascompletely reached a closing position. This leaves the exhaust valveclosure open, very slightly, and the force of the explosion on thepiston is consequently weakened. By reason of the fact that my protectortelescopes the guide outwardly and reaches for a considerable distancebelow the top of the guide, it will be seen that deposits' cannotaccumulate on the stem. 'Furthermore. my improved device only has aminute annular peripheral engagement with the guidea11d thus'if carbondeposits on the guide, it will be continually scraped off down to the ldiameter of the sharp edge of the hood, thereby preventing anyaccumulation of the deposit beyond such diameter.

While there will be a deposit of carbon on the guide, this constantdeposit will serve a utility, in the case of my invention, beca-use itwill act as a fill so that irrespective of the difference of contractionas between the hard metal hood and the cast iron guide,

there will always be a good working tit. Itv

is the purpose of my invention yto make the hood of hard metal and caseharden the edge 19.

By reason of the fact that the body of the hood 18 is much largerthanthe guide, and in view of the fact that the telescoping relation isestablished wholly by the inturned sharp edge, it will be seen that noform of deposit could ever wedge between the guide and the hood andretard the latter from free movement lengthwise of the former becausethe hood, above the sharp edge is in spaced relation to the guide.

The enlarged sleeve-like hood provides for such a considerable dead airspace that even during slow operation of an engine, when it isconsidered how rapidly the intake valve opens and closes, no air suctioncould induce anything like a flow eof air from between the inta-ke valvestem and its guide because the inertia of the dead air body would not beovercome until the valve had again closed.

lIt is believed that the novelty and utility of my invention, both inthe combination, andl as an article of manufacture, will be clear fromthe foregoing description, and while I have herein'shown and describedone specific form of my invention, I do not wish to be limited thereto.except for such limitations as the claimsvm( y import.

I claimy 1. In a protecting device for thatportion of an explosionengine valve stem between the closure and the guide, a sheet metal hoodiixed to and housing such portion of the stem and extending about. andhaving an i11- turned annular sharp. edge slidable connection with theguide for a suflicient distance tov completely' house such portion ofthe stem irrespective of the position of saidclosure. y 2. In aprotecting'device for that portion of an explosionengine valve stembetweenthe closure and the cast iron guide, a hood fixed to said 'stemin abutting relation to said closure and the remaining portion extendingabout' said stem and about said guide for a sufficient distance to housesuch portion of the stem irrespective of the position of said closure,and s'aid hood being of hard metal and having an inturned hardenedsharpedged flange engaging the periphery of said guide with a.sc1apingaction whereby the fill of the deposits on the periphery of said guidewill assure a closet-it operative slidable connection of said edgeagainst said guide lirrespective of the dilierence of co-eiiicience ofcontraction ofsaid hood and guide.

3. In a .protecting device for that portion of an explosion engine valvestem between A the closure and the guide, a sheet metal hood adapted tobe fixed in tight relation against the stem and adapted to engage saidclosure and the remainder of the hood being en larged with respect tothe stem and having an inturned annular edge adapted to slidably engagethe periphery of said guide to present a relatively considerable deadair body in said hood resisting ingress or egress passage of air `andparticles *from between said stem and guide.

4. In a protectingdevice for that portion the closure and the guidetherefor, a hood -of an explosion engine valve stem between having acontracted neck tight] .fitting about 'said steIIi and being secure .tosaid stem, the remainder of said hood being "enl lau-ged into Widelyspaced .relation to said vstem and yguide and having an inturnedsharpened. edge slidably en V a ing the l.PP/f* riphery of said guideasu g ment distance ther'elong to nclose saidfstem irres ective 0f theposition of saidV closure, Where* y the deed air body 'inisaid hood ispresented to- 10 resist ingress ory egress from between said stemandguide.

WILLIAM P. LWTHER.

